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US5807263A
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US
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Imaging of biological tissue using photon migration with high directionality techniques
Assignee: Non Invasive Technology Inc
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Filing: 1993-06-17
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Granted: 1998-09-15
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Expires: 2013-06-17
Abstract
Abstract A method and system for examination of a subject positioned between input and detection ports of the spectroscopic system applied to the subject. The systems shown include at lease one light source for introducing at one or multiple input ports, electromagnetic non-ionizing radiation of a known time-varying pattern of photon density of a wavelength selected to be scattered and absorbed while migrating in the subject, radiation pattern control means for achieving a directional pattern of emitted resulting radiation that possesses substantial gradient of photon density, at least one detector for detecting the radiation that has migrated in the subject at one or multiple detection ports. The systems also include processing means for processing the detected radiation and creating sets of data, and evaluation means for examining the subject using the data sets. The emitted directional radiation pattern utilizes its gradient of photon density to detect a hidden object while scanning across the examined subject. The wavelength of the radiation can be selected to be sensitive to endogenous or exogenous pigments, or to cause fluorescent emission from a fluorescent constituent of interest in the subject. The operation of the systems is computer controlled.
Inventors
- 👤 Britton Chance
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 22:49
CPC Classifications
G; G01; G01N; G01N21/00; G01N21/62; G01N21/63; G01N21/64; G01N21/645; G01N21/6456; A; A61; A61B; A61B5/00; A61B5/0059; A61B5/0073; A61B5/0082; A61B5/0091; A61B5/145; A61B5/1455; A61B5/14551; A61B5/14553; A61B5/43; A61B5/4306; A61B5/4312; G01N21/17; G01N21/25; G01N21/31; G01N21/314; G01N21/3151; G01N21/47; G01N21/4795; G01N21/49; G01N21/6486; A61B2562/00; A61B2562/02; A61B2562/0233; A61B2562/0242; A61B2562/04; A61B2562/043; A61B5/72; A61B5/7235; A61B5/7239; G01N2021/1789; G01N2021/3181; G01N2021/6417; G01N2021/6421; G01N2021/6484; G01N2201/00; G01N2201/06; G01N2201/069; G01N2201/0696
Claims Analysis
Total Claims: 78
Claim 1
Independent Claim
284 words
A spectroscopic system for examination of biological tissue comprising: at least one light source, operatively connected to at least one oscillator, constructed to generate optical radiation of a visible or infrared wavelength, said radiation being intensity modulated at a selected frequency of said oscillator to achieve a known radiation pattern, multiple input ports, placed at selected locations relative to the examined tissue, optically connected to said at least one light source and constructed to introduce simultaneously optical radiation to the examined tissue at the corresponding tissue locations, a radiation pattern controller constructed to control the radiation intensity or phase relationship of patterns simultaneously introduced from said multiple input ports, said introduced patterns forming resulting radiation that possesses a substantial gradient of photon density in at least one direction, said resulting radiation being scattered and absorbed in migration paths in the examined tissue, a detection port placed at a selected location relative to the examined tissue, an optical detector, optically connected to said detection port, constructed and arranged to detect over time the resulting radiation that has migrated in the tissue to said detection port, a processor, operatively connected to and receiving signal from said detector, arranged to process signals of said detected radiation in relation to said introduced radiation to create processed data indicative of influence of the examined tissue upon said substantial gradient of photon density of said resulting radiation, and an imager, including a display, connected to and receiving said processed data from said processor, said imager being constructed to produce image data representing the influence of the examined tissue upon said substantial gradient of photon density over a multiplicity of detection locations and to display said image data on said display.
Claim 2
Dependent Claim
284 words
A spectroscopic system for examination of biological tissue comprising: at least one light source, operatively connected to at least one oscillator, constructed to generate optical radiation of a visible or infrared wavelength, said radiation being intensity modulated at a selected frequency of said oscillator to achieve a known radiation pattern, multiple input ports, placed at selected locations relative to the examined tissue, optically connected to said at least one light source and constructed to introduce simultaneously optical radiation to the examined tissue at the corresponding tissue locations, a radiation pattern controller constructed to control the radiation intensity or phase relationship of patterns simultaneously introduced from said multiple input ports, said introduced patterns forming resulting radiation that possesses a substantial gradient of photon density in at least one direction, said resulting radiation being scattered and absorbed in migration paths in the examined tissue, a detection port placed at a selected location relative to the examined tissue, an optical detector, optically connected to said detection port, constructed and arranged to detect over time the resulting radiation that has migrated in the tissue to said detection port, a processor, operatively connected to and receiving signal from said detector, arranged to process signals of said detected radiation in relation to said introduced radiation to create processed data indicative of influence of the examined tissue upon said substantial gradient of photon density of said resulting radiation, and an imager, including a display, connected to and receiving said processed data from said processor, said imager being constructed to produce image data representing the influence of the examined tissue upon said substantial gradient of photon density over a multiplicity of detection locations and to display said image data on said display.
Claim 3
Dependent Claim
28 words
The system of claim 1 wherein said multiple input ports are arranged to form a one dimensional array shaped to examine a selected organ of a human body.
Claim 4
Dependent Claim
29 words
The system of claim 1 wherein said multiple input ports are arranged to form a two dimensional array is shaped to examine a selected organ of a human body.
Claim 5
Dependent Claim
17 words
The system of claim 2 or 3 wherein said shape fits a head or a female breast.
Claim 6
Dependent Claim
49 words
The system of claim 1 wherein said wavelength is sensitive to a wavelength sensitive agent present in the examined tissue and said processed data also indicate of the influence of said wavelength sensitive agent upon said steep phase change or said sharp minimum in the intensity of said radiation.
Claim 7
Dependent Claim
35 words
The system of claim 1 further comprising a phase detector, connected to and receiving signals from said optical detector, constructed to detect the phase of the detected radiation, said phase being utilized by said imager.
Claim 8
Dependent Claim
35 words
The system of claim 1 further comprising an amplitude detector, connected to and receiving signals from said optical detector, constructed to detect the amplitude of the detected radiation, said amplitude being utilized by said imager.
Claim 9
Dependent Claim
32 words
The system of claim 1 further comprising a second light source, optically connected to said input ports, constructed to generate radiation of a second selected wavelength in the visible or infrared range.
Claim 10
Dependent Claim
89 words
The system of claim 1 further comprising: a second detection port placed at a selected location relative to the examined tissue, an second optical detector, optically connected to said second detection port, constructed and arranged to detect over time the resulting radiation that has migrated in the tissue to said detection port, and said processor, receiving signal from said first detector and said second detector, further arranged to process signals of said first detector and said second detector in a relative phase shifted relationship to create said processed data.
Claim 11
Dependent Claim
27 words
The system of claim 9 wherein said relative phase shifted relationship comprises a 180 degree phase shift between said first detector signal and said second detector signal.
Claim 12
Dependent Claim
268 words
A spectroscopic system for examination of biological tissue comprising: at least one light source, operatively connected to at least one oscillator, constructed to generate optical radiation of a visible or infrared wavelength, said radiation being intensity modulated at a selected frequency of said oscillator to achieve a known radiation pattern, multiple input ports, placed at selected locations relative to the examined tissue, optically connected to said at least one light source and constructed to introduce simultaneously optical radiation to the examined tissue at the corresponding tissue locations, a radiation pattern controller constructed to control the radiation intensity or phase relationship of patterns simultaneously introduced from said multiple input ports, said introduced patterns forming resulting radiation that possesses a substantial gradient of photon density in at least one direction, said resulting radiation being scattered and absorbed in migration paths in the examined tissue, a detection port placed at a selected location relative to the examined tissue, an optical detector, optically connected to said detection port, constructed and arranged to detect over time the resulting radiation that has migrated in the tissue to said detection port, a processor, operatively connected to and receiving signal from said detector, arranged to process signals of said detected radiation in relation to said introduced radiation to create localization signals indicative of influence of the examined tissue upon said substantial gradient of photon density of said radiation, and an imager, including a display, connected to and receiving said localization signals from said processor and being constructed to display said localization signals indicating scattering or absorption of the examined tissue over a multiplicity of detection locations.
Claim 13
Dependent Claim
268 words
A spectroscopic system for examination of biological tissue comprising: at least one light source, operatively connected to at least one oscillator, constructed to generate optical radiation of a visible or infrared wavelength, said radiation being intensity modulated at a selected frequency of said oscillator to achieve a known radiation pattern, multiple input ports, placed at selected locations relative to the examined tissue, optically connected to said at least one light source and constructed to introduce simultaneously optical radiation to the examined tissue at the corresponding tissue locations, a radiation pattern controller constructed to control the radiation intensity or phase relationship of patterns simultaneously introduced from said multiple input ports, said introduced patterns forming resulting radiation that possesses a substantial gradient of photon density in at least one direction, said resulting radiation being scattered and absorbed in migration paths in the examined tissue, a detection port placed at a selected location relative to the examined tissue, an optical detector, optically connected to said detection port, constructed and arranged to detect over time the resulting radiation that has migrated in the tissue to said detection port, a processor, operatively connected to and receiving signal from said detector, arranged to process signals of said detected radiation in relation to said introduced radiation to create localization signals indicative of influence of the examined tissue upon said substantial gradient of photon density of said radiation, and an imager, including a display, connected to and receiving said localization signals from said processor and being constructed to display said localization signals indicating scattering or absorption of the examined tissue over a multiplicity of detection locations.
Claim 14
Dependent Claim
22 words
The system of claim 11 wherein said processor further comprises a phase detector constructed to detect the phase of the detected radiation.
Claim 15
Dependent Claim
22 words
The system of claim 11 wherein said processor further comprises an amplitude detector constructed to detect the amplitude of the detected radiation.
Claim 16
Dependent Claim
28 words
The system of claim 1, or 11 wherein said phase relationship of radiation patterns introduced from two adjacent input ports of said multiple input ports is 180 degrees.
Claim 17
Dependent Claim
32 words
The system of claim 11 further comprising a second light source, optically connected to said input ports, constructed to generate radiation of a second selected wavelength in the visible or infrared range.
Claim 18
Dependent Claim
18 words
The system of claim 15 further constructed to introduce said radiation of said wavelengths in a time-shared manner.
Claim 19
Dependent Claim
29 words
The system of claim 11 wherein said multiple input ports are arranged to form a one dimensional array shaped to examine a selected tissue region of a human body.
Claim 20
Dependent Claim
30 words
The system of claim 11 wherein said multiple input ports are arranged to form a two dimensional array is shaped to examine a selected tissue region of a human body.
Claim 21
Dependent Claim
17 words
The system of claim 17 or 18 wherein said shape fits a head or a female breast.
Claim 22
Dependent Claim
43 words
The system of claim 1 or 11 further comprising multiple detection ports optically connected to at least one said detector and placed at selected locations relative to the examined tissue, said detection ports forming a one dimensional array or a two dimensional array.
Claim 23
Dependent Claim
28 words
The system of claim 1 or 11 wherein said processor further calculates from said processed data an absorption coefficient μ a or a scattering coefficient μ s .
Claim 24
Dependent Claim
38 words
The system of claim 11 wherein said resulting radiation forms a cone scanning in the examined tissue and said localization signals include a non-symmetrical pattern indicating presence of an abnormal tissue region of different scattering or absorption properties.
Claim 25
Dependent Claim
19 words
The system of claim 1 or 11 wherein said input and detection ports are arranged in a transmission geometry.
Claim 26
Dependent Claim
51 words
The system of claim 1 or 11 wherein said wavelength is sensitive to a wavelength sensitive agent present in the examined tissue and said processed data also indicate of the influence of said wavelength sensitive agent upon said steep phase change or said sharp minimum in the intensity of said radiation.
Claim 27
Dependent Claim
18 words
The system of claim 11 wherein said imager further employs a contrast enhancing algorithm on said localization signals.
Claim 28
Dependent Claim
21 words
The system of claim 11 wherein said imager further employs a contrast enhancing algorithm that includes differentiation of the localization signals.
Claim 29
Dependent Claim
21 words
The system of claim 11 wherein said imager further employs a contrast enhancing algorithm that includes integration of the localization signals.
Claim 30
Dependent Claim
49 words
The system of claim 1 or 11 wherein said radiation pattern controller is constructed to alter the relative phase, the relative amplitude or the relative frequency of said introduced radiation patterns to achieve electronic scanning of said gradient of photon density of said resulting radiation over the examined tissue.
Claim 31
Dependent Claim
32 words
The system of claim 1 or 11 further comprising a mechanical scanning device constructed to move said input ports to different locations on a predetermined geometric pattern relative to the examined tissue.
Claim 32
Dependent Claim
33 words
The system of claim 1 or 11 further comprising a mechanical scanning device constructed to move said detection port to a different location on a predetermined geometric pattern relative to the examined tissue.
Claim 33
Dependent Claim
23 words
The system of claim 1 or 11 wherein said oscillator operates at a frequency in the range of 40 MHz to 1 GHz.
Claim 34
Dependent Claim
18 words
The system of claim 1 or 11 wherein said oscillator operates at a frequency of about 50 MHz.
Claim 35
Dependent Claim
20 words
The system of claim 32 wherein said light source is a LED diode and said detector is a diode detector.
Claim 36
Dependent Claim
18 words
The system of claim 1 or 11 wherein said oscillator operates at a frequency of about 200 MHz.
Claim 37
Dependent Claim
19 words
The system of claim 34 wherein said light source is a laser diode and said detector is a PMT.
Claim 38
Dependent Claim
30 words
The system of claim 1 or 11 wherein said substantial gradient of photon density includes a steep phase change or a sharp minimum in the intensity of said resulting radiation.
Claim 39
Dependent Claim
30 words
The system of claim 1 or 11 wherein said wavelength of said light source is 754 nm, 760 nm, 780 nm, 800 nm, 816 nm, 840 nm or 850 nm.
Claim 40
Dependent Claim
25 words
The system of claim 1 or 11 wherein said oscillator is an element of a double side band modulator constructed to produce said intensity modulation.
Claim 41
Dependent Claim
17 words
The system of claim 1 or 11 wherein said detector is a photomultiplier constructed for heterodyne detection.
Claim 42
Dependent Claim
228 words
A spectroscopic method of examination of biological tissue of a subject, comprising the steps: providing at least one light source of electromagnetic radiation of a visible or infrared wavelength, said radiation being intensity modulated at a selected frequency, said source being optically connected to multiple input ports, and further providing a detection port optically connected to an optical detector; introducing simultaneously into the examined tissue, at said input ports, said intensity modulated radiation having a known time-varying pattern of photon density, a time relationship, radiation intensity or phase of said patterns being selected by a pattern controller to form resulting introduced radiation that possesses, in at least one direction, a substantial gradient in photon density as a result of interaction of the simultaneously introduced patterns emanating from said input ports, said resulting radiation being scattered and absorbed in migration paths in the examined tissue; detecting over time, at a detection port placed at a selected location on the examined tissue, said radiation that has migrated in the examined tissue; processing signals of said detected radiation in relation to said introduced radiation to create processed data indicative of influence of said examined tissue upon said substantial gradient of photon density; and imaging the examined tissue by displaying image data representing the influence of the examined tissue upon said substantial gradient of photon density over a multiplicity of detection locations.
Claim 43
Dependent Claim
228 words
A spectroscopic method of examination of biological tissue of a subject, comprising the steps: providing at least one light source of electromagnetic radiation of a visible or infrared wavelength, said radiation being intensity modulated at a selected frequency, said source being optically connected to multiple input ports, and further providing a detection port optically connected to an optical detector; introducing simultaneously into the examined tissue, at said input ports, said intensity modulated radiation having a known time-varying pattern of photon density, a time relationship, radiation intensity or phase of said patterns being selected by a pattern controller to form resulting introduced radiation that possesses, in at least one direction, a substantial gradient in photon density as a result of interaction of the simultaneously introduced patterns emanating from said input ports, said resulting radiation being scattered and absorbed in migration paths in the examined tissue; detecting over time, at a detection port placed at a selected location on the examined tissue, said radiation that has migrated in the examined tissue; processing signals of said detected radiation in relation to said introduced radiation to create processed data indicative of influence of said examined tissue upon said substantial gradient of photon density; and imaging the examined tissue by displaying image data representing the influence of the examined tissue upon said substantial gradient of photon density over a multiplicity of detection locations.
Claim 44
Dependent Claim
112 words
The method of claim 40 further comprising the steps of moving synchronously said input ports or said detection port to different locations on a predetermined geometric pattern relative to the examined tissue; introducing into the examined tissue, at each said input port, said radiation; detecting over time, at said detection port said radiation that has migrated in the examined tissue; processing signals of said detected radiation in relation to said introduced radiation to create processed data indicative of the influence of said examined tissue upon said gradient of photon density; and imaging the examined tissue of said different location by displaying image data created from said processed data received from said processor.
Claim 45
Dependent Claim
97 words
The method of claim 40 further comprising the steps of introducing said radiation while electronically scanning said gradient of photon density of said resulting radiation over the examined tissue; detecting over time, at said detection port said radiation that has migrated in the examined tissue; processing signals of said detected radiation in relation to said introduced radiation to create processed data indicative of the influence of said examined tissue upon said gradient of photon density; and imaging the examined tissue of said different location by displaying image data created from said processed data received from said processor.
Claim 46
Dependent Claim
29 words
The method of claim 42 wherein said electronic scanning step is performed by varying the relative phase, the relative amplitude or the relative frequency of said introduced radiation patterns.
Claim 47
Dependent Claim
26 words
The method of claim 40, 41 or 42 further comprising the step of positioning said detection port in the direction of said gradient of photon density.
Claim 48
Dependent Claim
27 words
The method of claim 40, 41 or 42 further comprising the step of detecting the phase of said detected radiation and utilizing said phase in said imaging.
Claim 49
Dependent Claim
27 words
The method of claim 40, 41 or 42 further comprising the step of detecting the amplitude of said detected radiation and utilizing said amplitude in said imaging.
Claim 50
Dependent Claim
111 words
The method of claim 40, 41 or 42 further comprising the steps of introducing, at each said input port, said radiation of a second selected wavelength in the visible or infrared range; detecting over time, at said detection port said radiation of said second selected wavelength that has migrated in the examined tissue; processing signals of said detected radiation of said second selected wavelength in relation to said introduced radiation of said second selected wavelength to create processed data indicative of the influence of said examined tissue upon said gradient of photon density; and imaging the examined tissue by displaying image data created from said processed data received from said processor.
Claim 51
Dependent Claim
92 words
The method of claim 40 further comprising the steps of: detecting over time, at multiple detection ports placed at selected locations relative to the examined tissue, said radiation that has migrated in the examined tissue, said detection ports forming a one dimensional array or a two dimensional array; processing signals of said detected radiation in relation to said introduced radiation to create processed data of multiple detection ports indicative of the influence of the examined tissue upon said gradient of photon density; and imaging the examined tissue by displaying said image data.
Claim 52
Dependent Claim
59 words
The method of claim 40 further comprising the steps of: detecting over time, at two detection ports placed at selected locations relative to the examined tissue, said radiation that has migrated in the examined tissue, processing signals detected at said first detection port and said second detection port in a relative phase shifted relationship to create said processed data.
Claim 53
Dependent Claim
35 words
The method of claim 49 wherein said relative phase shifted relationship comprises a 180 degree phase shift between the signal detected at said first detection port and the signal detected at said second detection port.
Claim 54
Dependent Claim
227 words
A spectroscopic method of examination of biological tissue of a subject, comprising the steps: providing at least one light source of electromagnetic radiation of a visible or infrared wavelength, said radiation being intensity modulated at a selected frequency, said light source being optically connected to multiple input ports, and further providing a detection port optically connected to an optical detector; introducing simultaneously into the examined tissue, at each said input port, said intensity modulated radiation of a known time-varying pattern of photon density, a relative time relationship, radiation intensity or phase of said introduced patterns being selected by a pattern controller to form resulting radiation that possesses, in at least one direction, a substantial gradient in photon density as a result of interaction of the simultaneously introduced patterns emanating from said input ports, said resulting radiation being scattered and absorbed in migration paths in the examined tissue; detecting over time, at a detection port placed at a selected location relative to the examined tissue, said radiation that has migrated in the examined tissue; processing signals of said detected radiation in relation to said introduced radiation to create localization signals indicative of influence of the examined tissue upon said substantial gradient of photon density; and imaging the examined tissue by displaying said localization signals indicating scattering or absorption of the examined tissue over a multiplicity of detection locations.
Claim 55
Dependent Claim
227 words
A spectroscopic method of examination of biological tissue of a subject, comprising the steps: providing at least one light source of electromagnetic radiation of a visible or infrared wavelength, said radiation being intensity modulated at a selected frequency, said light source being optically connected to multiple input ports, and further providing a detection port optically connected to an optical detector; introducing simultaneously into the examined tissue, at each said input port, said intensity modulated radiation of a known time-varying pattern of photon density, a relative time relationship, radiation intensity or phase of said introduced patterns being selected by a pattern controller to form resulting radiation that possesses, in at least one direction, a substantial gradient in photon density as a result of interaction of the simultaneously introduced patterns emanating from said input ports, said resulting radiation being scattered and absorbed in migration paths in the examined tissue; detecting over time, at a detection port placed at a selected location relative to the examined tissue, said radiation that has migrated in the examined tissue; processing signals of said detected radiation in relation to said introduced radiation to create localization signals indicative of influence of the examined tissue upon said substantial gradient of photon density; and imaging the examined tissue by displaying said localization signals indicating scattering or absorption of the examined tissue over a multiplicity of detection locations.
Claim 56
Dependent Claim
112 words
The method of claim 51 further comprising the steps of moving synchronously said input ports or said detection port to a different location on a predetermined geometric pattern relative to the examined tissue; introducing into the examined tissue, at each said input port, said radiation; detecting over time, at said detection port said radiation that has migrated in the examined tissue; processing signals of said detected radiation in relation to said introduced radiation to create localization signals indicative of the influence of said examined tissue upon said gradient of photon density; and imaging the examined tissue by displaying said localization signals of said location indicating scattering or absorption of the examined tissue.
Claim 57
Dependent Claim
97 words
The method of claim 51 further comprising the steps of introducing said radiation while electronically scanning said gradient of photon density of said resulting radiation over the examined tissue; detecting over time, at said detection port said radiation that has migrated in the examined tissue; processing signals of said detected radiation in relation to said introduced radiation to create localization signals indicative of the influence of said examined tissue, by said electronic scanning, upon said gradient of photon density; and imaging the examined tissue by displaying said localization signals indicating scattering or absorption of the examined tissue.
Claim 58
Dependent Claim
29 words
The method of claim 53 wherein said electronic scanning step is performed by varying the relative phase, the relative amplitude or the relative frequency of said introduced radiation patterns.
Claim 59
Dependent Claim
23 words
The method of claim 51, 52 or 53 further comprising locating said detection port in the direction of said gradient of photon density.
Claim 60
Dependent Claim
32 words
The method of claim 51, 52 or 53 further comprising the step of detecting the phase of said detected radiation and utilizing said phase in said step of producing said localization signals.
Claim 61
Dependent Claim
32 words
The method of claim 51, 52 or 53 further comprising the step of detecting the amplitude of said detected radiation and utilizing said amplitude in said step of producing said localization signals.
Claim 62
Dependent Claim
27 words
The method of claim 56 further comprising the step of calculating from said processed data an absorption coefficient μ a or a scattering coefficient μ s .
Claim 63
Dependent Claim
28 words
The method of claim 40 or 51 wherein the phase relationship of radiation patterns introduced from two adjacent input ports of said multiple input ports is 180 degrees.
Claim 64
Dependent Claim
26 words
The method of claim 40 or 51 wherein said introducing and detecting steps are performed having said input and detection ports arranged in a transmission geometry.
Claim 65
Dependent Claim
23 words
The method of claim 60 wherein said imaging step further comprises the step of employing a contrast enhancing algorithm on said localization signals.
Claim 66
Dependent Claim
26 words
The method of claim 60 wherein said imaging step further comprises the step of employing a contrast enhancing algorithm that includes differentiation of the localization signals.
Claim 67
Dependent Claim
26 words
The method of claim 60 wherein said imaging step further comprises the step of employing a contrast enhancing algorithm that includes integration of the localization signals.
Claim 68
Dependent Claim
30 words
The method of claim 40 or 51 further comprising the step of varying frequency of the introduced radiation to alter migration path of said resulting radiation in the examined tissue.
Claim 69
Dependent Claim
24 words
The method of claim 40 or 51 wherein said frequency of the introduced radiation is in the range of 40 MHz to 1 GHz.
Claim 70
Dependent Claim
18 words
The method of claim 40 or 51 wherein said frequency is about 50 MHz or about 200 MHz.
Claim 71
Dependent Claim
29 words
The method of claim 40 or 51 wherein said substantial gradient of photon density includes a steep phase change or a sharp minimum in the intensity of said radiation.
Claim 72
Dependent Claim
26 words
The method of claim 40 or 51 wherein said wavelength of said light source is sensitive to a wavelength sensitive agent present in the examined tissue.
Claim 73
Dependent Claim
30 words
The method of claim 40 or 51 wherein said wavelength of said light source is 754 nm, 760 nm, 780 nm, 800 nm, 816 nm, 840 nm or 850 nm.
Claim 74
Dependent Claim
23 words
The method of claim 40 or 51 wherein said wavelength of said light source is sensitive to an endogenous or an exogenous pigment.
Claim 75
Dependent Claim
19 words
The method of claim 40 or 51 wherein said intensity modulation is performed by a double side band modulator.
Claim 76
Dependent Claim
20 words
The method of claim 40 or 51 wherein said detector is a photomultiplier and said detecting step includes heterodyne detection.
Claim 77
Dependent Claim
35 words
The method of claim 40 or 51 further comprising the steps of introducing radiation of a second wavelength, said radiation being intensity modulated at said frequency and having said known time-varying pattern of photon density.
Claim 78
Dependent Claim
21 words
The method of claim 73 wherein said steps of introducing said radiation of said wavelengths is performed in a time-shared manner.
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